The header of an agricultural harvester or combine is provided with row dividers and associated hoods for directing rows of corn stalks to downstream separation devices known as row units. The row units include stalk receiving slots and stripping plates, snapping rolls, and opposed rearwardly moving gathering chains. Thus, e.g., following separation of ears from stalks by the snapping rolls and stripping plates (also known as stalk rolls and deck plates, respectively), the separated ears are delivered by the gathering chains to an auger which conveys the harvested ears to a feederhouse of the combine. Harvested ears are then processed to the combine's inner chambers for downstream processing.
Row unit frames are typically constructed with forwardly projecting members that support several components of the row unit including the deck plates, the stalk roll support bearings, the front gathering chain idlers, the hoods and the row dividers. The deck plates are flat or planar with their shape being dictated by the geometry of the row unit frames. As is known, the stalk rolls are disposed beneath the deck plates and are cooperatively rotated to pull the corn stalks downwardly into the stalk receiving slots where the ears come into contact with the deck plates and are snapped off of the stalks by the deck plates. The deck plates lie generally tangent to the upper surfaces of the stalk rolls and the stalk rolls engage the corn stalks at “pinch points” situated below the upper surfaces of deck plates.
The deck plates are generally provided in pairs defining a gap therebetween, allowing the corn stalks to enter the gap before being pulled down to the deck plates so the corn ear snaps off the stalk. Traditionally, deck plates had a fixed gap therebetween which was set by an operator. If the gap is too small for the stalk(s) encountered by the header, generally the stalk is severed rather than the corn ear snapping off the stalk, admitting a high percentage of stalks into the combine. If the gap is too large for the stalk(s) encountered by the header, large losses of shelled corn can result. Recent advances have provided adjustable deck plates that allow adjustment of the gap during operation of the header. However, the issues of excessive stalk admission into the combine and loss still remain, especially in fields where the stalk diameters vary greatly.
What is needed in the art is a header which can address some of the previously described shortcomings of known headers.